It is known to provide a piece of machinery with an automatic lubricant dispenser that is pressurized to force a fluent lubricant, normally an oil or grease, along a conduit into a part, typically a bearing, of the machine. In order to avoid having to provide a pump it has been suggested to provide a gas-generating cell which pressurizes the lubricant by means of a chemical reaction that can be initiated by the user when the dispenser is connected to the machine, and that generates sufficient gas to deplete the entire supply of lubricant in the dispenser.
German patent document 3,811,469 filed Apr. 6, 1988 by B. Jorissen describes a system where the vessel containing the lubricant is fitted with a complete gas-generating cell comprising a compartment containing a reactive liquid and a cartridge defining a compartment containing an active-alloy metal that can react with the liquid to generate a gas. The cartridge is screwed into the cell to activate the chemical reaction and drive down a separate piston that is provided in the vessel. A similar system id described in German patent document 1,256,001 filed Jul. 21, 1964 by G. Satzinger as well as in U.S. Pat. Nos. 5,012,897 and 5,386,883, and U.S. patent application Ser. Nos. 08/156,564, 08/264,479, 08/276,084, and 08/303,353.
The reactive element for such a dispenser typically is formed as a part of two separate metals, one more active, that is higher in the electromotive series, than the other. In a standard system a plate or wafer of zinc is formed with a hole or recess in which is set or soldered a nickel-coated plug of molybdenum. When such an element is immersed in citric acid, hydrogen is generated.
While such an element works well, it often does not react as well as desired and is frequently difficult to manufacture.